CloudHospital

Last updated date: 11-Mar-2024

Medically Reviewed By

Medically reviewed by

Dr. Hakkou Karima

Medically reviewed by

Dr. Lavrinenko Oleg

Originally Written in English

Hives – Symptoms, Causes and Treatment

     

    Hives Definition

    Hives (also known as urticaria or nettle rash) are the sudden appearance of pale red lumps or weals on the skin as a result of the body's allergic reaction to a specific chemical. These weals range in size from 1 mm to many centimeters in 'giant urticaria,' and are often itchy. They are induced by vasoactive mediators, primarily histamine, which are produced by mast cells. These skin eruptions can arise anywhere on the body, creating itching that can be severe and difficult to tolerate at times.

    In the great majority of instances, the weals are temporary, lasting only a few hours in one location before reappearing in another. This means that most rashes move over the body, which is a useful clinical history indicator that the rash is urticarial.

    Once the allergic reaction has been triggered, the body releases a biological substance called histamine in the tissues contributing to the dilating of the blood vessels, making their walls extremely thin and permeable. The swelling of the skin that’s caused by this allergic reaction is referred to as edema.

    In this article, we will discuss hive's types, what causes it, its symptoms, what are some medical conditions associated with it, and finally how exactly we can treat it!

     

    Types of Hives

    The current definitions and classification stratify urticaria according to time course and etiology:

    • Acute spontaneous urticaria: 

    It’s the most common type of hive, lasting less than six weeks. It is usually caused by reactions to food, medication, infection, or bug and insect bites. Spontaneous occurrence of wheals and/or angioedema for a total duration of fewer than six weeks.

    • Chronic spontaneous urticaria (CSU): 

    Spontaneous occurrence of wheals and/or angioedema for a total duration of six weeks or more and can reappear frequently over months/years. In this case, however, it is very difficult to pinpoint the cause as for some people chronic urticaria is associated with other pre-existing medical conditions, such as thyroid dysfunction, cancer, or hepatitis. What’s more is that this type of hives can also affect the interior of the body, with the gastrointestinal tract, the lungs, and the muscle being the ones affected. This is synonymous with "chronic urticaria" and "chronic idiopathic urticaria."

    • Chronic inducible urticaria (CIndU): 

    This is the classic expression of hives, representing the immune system’s response to contact with a trigger/an allergen. Usually, the bumps and welts develop in the exact area of skin that was in contact with the trigger, disappearing approximately an hour after contact.  The occurrence of wheels for a period of six weeks or more is caused by physical reasons (e.g., touch, pressure extremes). This is the same as "physical urticaria."

    • Dermatographism

     This particular type of hive is caused by scratching or stroking the skin in an excessive way. Given the fact that hives almost always are extremely itchy, dermatographism can appear as a result of scratching the pre-existing bumps caused by other factors.   

    • Papular urticaria. 

    These are the hives caused by insect and bug bites (mosquitos, fleas, mites, bed bugs). They are usually hives with blisters filled with fluid (vesicles) that vary in size and that are symmetrically aligned. They are not constant, appearing and disappearing in different areas and sometimes they can leave marks after they are healed. Because they are so inconstant in occurrence, it can take weeks or months before the person is completely healed. This type of hives is most common in children, but they can also appear in adults of any age.

     

    Hives causes

    Hives causes

    Considering that hives are an allergic reaction, the first question that comes to mind is what triggers it? The most common triggers (or allergens) for hives are:

    • some types of foods – cow milk, eggs, peanuts, nuts, soy, seafood, some proteins, different fruits, dust, etc.;
    • food additives and preservatives – especially salicylic acid or benzoates that can be found in pickles for example;
    • some medication – antibiotics, sedatives, some anesthetic substances, diuretics, laxatives, antacids, pain killers, anti-inflammatory drugs, different kinds of supplements, contrast substances (agents) that are used for CT/RMN or other imagistic investigations, rheumatoid medication, etc.; these can cause allergic reactions that could also be severe, especially if the recommended dose is not respected or followed;
    • some chemical agents – mostly the ones in cosmetic products (such as hair products) or in cleaning products;
    • environmental factors – hot or cold temperature, long exposure to the sun;
    • insect bites – the most common allergic reactions are caused by bites from wasps, bees, ants, spiders, mosquitos, bedbugs, flies;
    • emotional factors – when the nervous system is under stress, it can determine several dermatological effects such as hives.

     

    Hives from stress

    Hives are raised red lumps that occur as a result of stress rashes. A stress rash can appear anywhere on the body, although it most commonly appears on the face, neck, chest, or arms. Hives can range in size from microscopic spots to enormous welts and can appear in bunches. They may itch or give tingling or burning sensations.

    Acute urticaria can occur in response to a specific stressful incident, and financial, psychological, or professional stress can all aggravate chronic urticaria. The illness itself may be quite debilitating, lowering one's quality of life.

     

    Popular ways to Relieve Stress

    Meanwhile, there are certain things you can do to assist you to handle stress before it becomes too much. These suggestions may assist you in reducing stress:

    • Maintain an optimistic attitude.
    • Accept that there are certain circumstances that you cannot control.
    • Improve your time management skills.
    • Make time for your interests and hobbies.
    • Instead of being aggressive, be forceful. Instead of getting angry, defensive, or passive, express your thoughts, ideas, or beliefs.
    • Set proper limits and decline requests that may cause undue stress in your life.
    • Don't use alcohol, drugs, or obsessive habits. Drugs and alcohol can add to the stress on your body.
    • Spend enough time with the people you care about.

     

    Chronic Spontaneous Urticaria

    The cause of chronic spontaneous urticaria (CSU) is yet unknown. The prevalent theory is that it is related to autoimmune dysfunction caused by autoantibodies that target IgE and/or IgE receptors, causing basophils and mast cells to produce histamine.

    The increasing frequency of autoimmune illnesses among CSU patients lends more credence. The most prevalent of them is autoimmune hypothyroidism, which affects up to 9.8 percent of the population. Rheumatoid arthritis, systemic lupus erythematosus, Sjogren syndrome, celiac disease, and type 1 diabetes mellitus are all related illnesses.

    Infections caused by a range of species have also been linked to CSU. Bacteria (H. pylori, Streptococci, Staphylococci, Yersinia, Mycoplasma pneumonia), viruses (Hepatitis virus, Norovirus, Parvovirus B19), and parasites are among them (Giardia lamblia, Entamoeba spp., Anisakis simplex). Causality is yet unknown, however, it might entail an infection-mediated autoimmune response and molecular mimicry.

    Foods and chemicals are seldom the cause of CSU while being involved in acute IgE-mediated food allergy. The evidence suggesting a link between cancer and CSU is contradictory, with diverse investigations, including retrospective studies and systematic reviews, yielding inconsistent results.

     

    Epidemiology

    CSU is predicted to affect 0.23 % to 1.8 percent of the population in the United States and throughout the world. There is a definite feminine preference, with women being affected twice as often as males. Children and adults are both afflicted, while the frequency is higher among those aged 40 to 60.

     

    Pathophysiology

    Mast cell and basophil activation cause urticaria and angioedema. Immune mediators are released as a result of mast cell degranulation. Histamine is the major mediator, and it binds to H-receptors on endothelial cells and sensory neurons. Prostaglandins, leukotrienes, and a number of cytokines and chemokines are also implicated. This, in turn, causes vasodilatation - increased vascular permeability - and, as a result, cutaneous edema and the recruitment of inflammatory cells.

    Mast cell activation can be classified as immunological or non-immunological.

    • Mast cell effectors of adaptive immunity binding receptors induce immunological activation. Crosslinking of allergen with IgE on sensitized mast cells causes acute urticaria and anaphylaxis in type 1 hypersensitivity. Immunological activation of mast cells in CSU, on the other hand, is likely to occur independently of allergen-IgE complexes and may include IgG (type 2 hypersensitivity), circulating immune complexes (type 3 hypersensitivity), and T-cells (type 4 hypersensitivity).
    • Non-immunological activation can be triggered by physical conditions, such as chronic inducible urticaria, as well as food and medication molecules that are not mediated by adaptive immunity. The threshold for activation by external stimuli may be lower in CSU.

     

    Drug-related Urticaria

    Urticaria can be caused by a variety of medications. A common cause is the use of cyclo-oxygenase (COX) inhibitor medicines such as aspirin and NSAIDs. Opiates, especially codeine, may cause mast cell histamine release. Many over-the-counter analgesics contain aspirin, NSAIDs, and/or codeine, therefore it is critical to be explicit about which medications patients may or may not be allowed to use.

    These are not IgE-mediated responses, and specific IgE testing for aspirin, NSAIDs, and opiates is not recommended. Enhanced protein carbonylation and lipid peroxidation, as well as increased antioxidant enzyme activity, have been reported in individuals who develop non-IgE-mediated drug-related urticaria; however, it is unclear whether this oxidative stress is the source or the result of the response.

    Angiotensin-converting enzyme inhibitors (ACEI) and statins induce isolated angioedema far more frequently than urticaria]. Urticarial responses can also be caused by radiocontrast media and plasma substitutes.

     

    Hives symptoms

    Hives symptoms

    Hive is a medical condition that is fairly easy to diagnose due to its symptoms that are very easily spotted on the skin. These symptoms include:

    • Erythema – Redness of the skin that disappears if you apply pressure; caused by the dilation of cutaneous blood vessels; erythema usually consists of batches of hives welts that can be different in size and shape;
    • Small bumps of the skin, similar to insect bites that can appear on different parts of the body;
    • Irritation of the skin, represented by itchiness and a burning sensation;
    • Skin lesions that can vary dimension-wise and can also disappear in a few minutes, hours, or days, but can reappear after some time in other spots;
    • Angioedema – swelling of the lips, eyelids, throat;  
    • Anaphylaxis – the most serious allergic reaction that consists of feelings of dizziness, difficulty breathing, and angioedema.

    Concurrent angioedema affects up to 40% of people and is characterized by subcutaneous or submucosal edema in non-dependent sites, most often the lips, peri-orbital area, genitals, and extremities. Instead of pruritus, patients complain of discomfort or pain. This can take up to 72 hours to resolve and is the major sign of CSU in 10% of individuals.

     

    Hives with fever

    If some of the symptoms of hives also include fever, shortness of breath, low blood pressure, nausea this can be a sign of a serious allergic reaction that requires medical assistance.

     

    Hives and diarrhea

    If hives and diarrhea co-occur, it’s most likely that you have an intestinal infection or a medical condition such as food poisoning, irritable bowel syndrome, traveler’s diarrhea, or stomach flu.

     

    Hives vs Rash

    We've seen what hives are, but what is a rash, and is it any different than hives or not? Well, the term “rash” is used to describe any kind of inflammation or coloration that makes the aspect of the skin unusual. A rash usually appears in one spot on the body and only in extreme cases, it can spread to the whole skin. The main symptoms of rashes are swelling of the skin and redness and sometimes blisters. Just like in the case of hives, the skin where there is a rash can be itchy or even painful.

    One important difference between hives and rashes is that rashes are caused by some medical conditions such as shingles, measles, chickenpox, or yeast infections. Three of the most common types of rashes are:

    • atopic dermatitis or eczema (which will be discussed later);
    • seborrheic dermatitis – usually caused by some characteristics specific to the environment in which the person lives (for example heat, humidity) or by genetic factors; it’s usually located on the scalp, having a greasy aspect;
    • contact dermatitis – as the name suggests, these rashes appear after the person has touched something that the skin didn’t quite like, causing irritation; most common causes are cosmetic or dermatological products, plants, or cleaning products.

     

    Hives Eczema

    Another type of skin reaction that is quite similar to hives is eczema or atopic dermatitis. Both are allergic reactions, but eczema is a chronic condition that most of the time involves the immune system. It usually affects children, but it can also appear in adults. 

    Some of the symptoms of eczema include dry and cracked skin, itchiness, parts of the skin that seem to have no color, bumps that may also have fluid, and periodic recurrence. Unlike hives, eczema usually appears in some specific parts of the body such as the face or the upper and lower limbs. 

    As far as what causes eczema, most of the time the triggers can be scratching, hot or cold weather, sweat, cleaning products, synthetic fabrics, allergens, or even stress. Even though eczema can be associated with medical conditions such as allergies or asthma (much like hives), the main difference between urticaria and eczema is that the latter is in most cases chronic, while the former is more of a one-time type of allergic response.  

     

    Hives vs Scabies

    While hives are an allergic reaction of the immune system to different types of allergens, scabies is an infectious reaction caused by the parasite “itch mite” or scabiei hominis. This parasite is invisible to the human eye and can be transmitted through contact with another individual that has the parasite or contact with animals. 

    It can also be transmitted through sexual contact or contact with an infected person’s clothes or personal items. The way these mites work is that it makes its way into the epidermis (the outer layer of the skin) and it lays eggs that will eventually turn into adult mites.

    In terms of symptoms, scabies causes severe itchiness, especially during the nighttime. The affected skin areas are usually red and similar to an insect bite, the most common areas affected being around the armpits or the toes. To diagnose scabies, describing the symptoms can help, but scraping the skin is the way to confirm the diagnosis because it can identify the mite.

     

    Hives with Flu?

    The flu is a respiratory infection that is very common and while until recently rashes and hives were not considered symptoms of the flu, now there is evidence that these conditions might have an association.

     

    Hives from Heat

    Some people get heat bumps or cholinergic urticaria (hives from heat) which are basically the hives you get whether you have just worked out and are sweaty, you are nervous for some reason or you’re just feeling extremely hot. The exact cause for cholinergic urticaria is not known, but it’s suspected that it could be caused either by a response of the nervous system or by an allergic reaction to sweat.

    The hives you get from high temperatures are usually small bumps with flares around, called wheals. They are warm and itchy and they can appear anywhere on the skin, with the face, chest, upper limbs and upper back being the most common areas. They don’t last long, appearing within approximately 5 to 6 minutes after the trigger and lasting approximately 30 minutes to an hour or two after.

    You might get cholinergic urticaria if you exercise intensely, take a hot shower, live in a hot climate, get angry, upset, or anxious, and even if you eat spicy foods. Therefore, as preventative measures, try to maintain a stable environment temperature-wise and avoid those situations that might cause you emotional stress.

     

    Hives from cold

    Another type of hives that is caused by extreme temperature is cold urticaria which is the skin’s response to cold temperatures. The symptoms are hives welts, itchiness, and redness, with the reaction intensifying once the skin is starting to warm up.

     people with cold urticaria can get swollen hands when touching cold objects or swollen lips when eating cold food or drinking cold beverages. This type of hives appears rather quick, just like cholinergic urticaria does and the most severe reactions can happen if the entire skin is exposed to low temperatures (e.g. swimming in cold water).

    The specific causes are not known, but it is possible that some people have extremely sensitive skin cells. There are some risk factors that make people predisposed to cold urticaria, such as age (it’s most prevalent in young adults), having an underlying medical condition (for example cancer), or having family members with the same condition (inheriting it).

     If you find yourself checking one or more of these boxes or you know that are prone to allergic reactions, there are a few measures you can take to prevent cold urticaria to appear, such as taking antihistamine medication before exposing yourself to cold temperatures, wearing adequate clothing or avoiding cold food and beverages.

     

    Hives from alcohol

    It's possible to also get hives from alcohol consumption, meaning that you’re most likely allergic to alcohol. This could happen within a few minutes to a few hours after ingesting alcohol.

    Some people are born with or develop what it’s called alcohol intolerance which means that their bodies reject and react negatively to alcohol. Some symptoms of alcohol intolerance are flushing (sometimes causing cholinergic urticaria), hives (bumps on the skin that are red and itchy), low blood pressure, nausea, diarrhea, asthma symptoms (usually they get worse if asthma is pre-existing).

    In terms of what causes alcohol intolerance or hives from alcohol, usually, the main cause is the lack of a specific enzyme responsible for the metabolism of the toxins in alcohol. It is usually genetically bound, this trait is most common in Asian people. Another cause can also be an allergy to grain or any other substance that can be found in alcoholic products.

     

    Hives from anxiety

    There is no secret by now that psychological conditions have a huge impact on the body. As such, apart from the psychological implications, stress and anxiety can also trigger physical and physiological symptoms. One of them is hives caused by stress. Stress rashes can be acute or chronic, depending on how long it takes for them to heal – acute if they disappear in less than 6 weeks, chronic if it takes longer.

    Stress and anxiety cause an imbalance in hormonal levels which in turn trigger the dilation of blood vessels that ultimately can lead to red and itchy spots on the skin. One thing to keep in mind is that there are some factors that can contribute to the worsening of the symptoms, such as temperature or alcohol consumption (as discussed before), which are linked to the consequences of stress.

    What's more, stress can also contribute to delaying the healing process of pre-existing skin conditions, such as psoriasis or eczema. Therefore, if you already suffer from any form of the dermatological condition, it is best that you keep your stress level under control in order for them to progress in the right direction.

     

    Hives Lupus?

    Typically, lupus doesn't cause hives. However, lupus can cause urticarial vasculitis which is the inflammation of the small blood vessels of the skin that can, in turn, cause hives. However, the welts caused by urticarial vasculitis can leave bruises, which is something that hives don’t do. Some other potential causes of hives in lupus could be the production of some antibodies in these patients that might determine an allergic response to a trigger or side effects from medication used to treat lupus.

     

    Hives and Thyroid Disease

    While the relationship between hives and thyroid disease hasn’t been discovered, some patients with thyroid dysfunctions develop hives, usually chronic hives (the type of hives that re-occurs). Research has found that some medication used to treat thyroid disease is also helpful in treating hives, the two medical conditions being quite similar in symptomatology.

     

    Hives pregnancy

    It’s quite common for pregnant women to experience different types of skin rashes due to the physical and hormonal changes they go through in that period of time. Hives are one of these skin conditions alongside heat rash or atopic eruption.

     

    Hives in babies

    Hives in babies

    Like any other human being, babies can get hives. Hives newborn could be pretty uncomfortable for the little one, causing itchiness and swelling and in some rare cases, they can also cause anaphylactic shock. However, the condition is not typically serious and can be treated easily.

    Hives in toddlers and hives in kids are quite common, this age group being the more predisposed to getting urticaria from food, bug bites or other allergens.  

     

    Hives diagnosis

    A full history is intended to uncover potential triggers and aggravating events as well as to rule out other diagnoses. This should investigate the time course and clinical features of the urticarial rash, associated angioedema, associated systemic and infective symptoms, personal or family history of allergies and autoimmune diseases, social and occupational history, induction by physical factors, newly administered medications, relationship to foods, and any exacerbating factors.

    If the patient is unable to recollect the sequence of wheals, drawing a circle around each individual lesion with a skin marking pen is effective for documenting remission within 24 hours. In the absence of a revealing history, an external reason for patients with CSU is exceedingly unlikely to be found.

    Routine diagnostic work-up for CSU is restricted to complete blood count and inflammatory markers (C-reactive protein and/or erythrocyte sedimentation rate), mostly to rule out other possible disorders. Atopy and parasite infection may be related to eosinophilia.

    Elevated inflammatory markers should raise the possibility of systemic illness. Further examinations in the absence of clinical suspicion, as guided by history, are unlikely to provide any new diagnosis. Skin prick testing is ineffective since type 1 allergies are seldom the cause of CSU. The efficacy and interpretation of autologous serum skin tests as a screen for autoantibodies to IgE and IgE receptors is a topic under investigation.

    Skin prick testing may be useful in determining if a person is atopic and if there are any specific contact antigens, such as foods or latex, that are likely to be urticaria triggers. 

     

    Hives treatment

     

    Hives how to treat?

    Just like in any other medical condition, the duration of treatment depends on the type and severity of the symptoms. Typically, hives are treated with antihistamines which is a type of hives medication that requires to be taken on a strict schedule. If antihistamines alone don’t seem to work, your doctor may prescribe oral steroids or cortisone medication. In case of anaphylactic shock, a hives cure consists of an injection of epinephrine.

    What is also extremely important is that the patient identifies the source of his allergic reaction and removes the trigger altogether, giving the medication and the immune system space to work their wonders.

    If you're a sceptic of medication, here are some hives natural remedies: cold compress on the swollen skin, keeping the temperature around you cool because heat can worsen the itchiness, or using an aloe vera skin patch for its anti-inflammatory proprieties. However, keep in mind that some symptoms of hives can be serious and can degenerate into a serious allergic reaction that requires immediate medical assistance.

     

    Antihistamines for Hives 

    Most kinds of urticaria, including chronic spontaneous urticaria and the vast majority of inducible urticarias, are mediated predominantly by mast cell-derived histamine, which reaches extremely high concentrations due to the dermal barrier's limited diffusibility.

    They are distinguished by short-lived wheals ranging in diameter from a few millimeters to several centimeters, which are accompanied by extreme itching, which is generally stronger in the evening or at night. Standard permitted dosages of H1-antihistamines are frequently unsuccessful in totally alleviating symptoms in many individuals, necessitating a four-fold increase in dosage.

    Thus, it is apparent that dermatologists look for the following characteristics in an H1-antihistamine: effectiveness, early start of the action, extended duration of the activity, and lack of side effects. Although some of these characteristics can be predicted from preclinical and pharmacokinetic investigations, they can only be firmly proved in the clinical setting.

    H-1 antihistamines are further subdivided into first-generation and second-generation medicines. First-generation H-1 antihistamines easily pass the blood-brain barrier into the CNS, but second-generation H-1 antihistamines do not.

    • First-generation: Antihistamines that make you feel sleepy – such as chlorphenamine, hydroxyzine, and promethazine
    • Second-generation: Non-drowsy antihistamines that are less likely to make you feel sleepy – such as cetirizine, diphenhydramine,  and loratadine

     

    Differential Diagnosis

    • Urticarial vasculitis is a kind of small vessel vasculitis that is characterized by wheals that last more than 24 hours, are associated with discomfort rather than an itch, and disappear with persistent ecchymosis and/or pigmentation.
    • Papular urticaria is a long-lasting insect bite reaction marked by clusters of pruritic papules, frequently with a central punctum.
    • Mastocytosis is a term used to describe a range of illnesses caused by the formation of clonal populations of mast cells in the skin and other organs. The Darier sign, which causes a wheal when the afflicted skin is rubbed, is pathognomonic.
    • In individuals who present with solitary angioedema in the absence of an urticarial rash, C1-esterase inhibitor deficiency, whether genetic or acquired, should be evaluated.
    • Bullous pemphigoid is an immunobullous illness that primarily affects the elderly. Pruritus and urticarial plaques define the pre-bullous phase, which progresses to tense bullae.
    • Anaphylaxis is a potentially fatal type I hypersensitivity reaction that most typically manifests abruptly as cutaneous hives and angioedema.

     

    Prognosis

    CSU is often self-limiting, lasting 3 to 5 years on average. Remission rates in the first 12 months have been reported to be as high as 80%. However, up to 14% of people may develop an illness that lasts longer than 5 years. Thyroid autoimmunity and concomitant angioedema are risk factors for a protracted illness course.

     

    Complications

    The pruritus caused by CSU can have a substantial negative impact on the patient's quality of life, interfering with both daily activities and sleep. CSU also has an adverse effect on health status ratings.

     

    FAQ about Hives

     

    1. Is the hive itchy? 

    Hives bumps and welts are the results of blood vessel dilation, causing the skin to stretch, expand and become irritable. All this leads to an intense sensation of itchiness that in some cases can be acute.

    However, there are some types of hives that don’t itch, for example, the ones that appear after intense scratching or rubbing of the skin (e.g. dermatographism).

     

    2. Are hives painful?

    Usually, hives are more itchy than painful, people with urticaria experience pain rather rare. However, hives caused by the inflammation of blood vessels (e.g. vasculitis) are painful and can leave bruises and marks on the skin, lasting for longer than a day or two.

     

    3. Are hives contagious?

    The short answer is no. Hives represent a reaction of the immune system to an allergen, causing an allergic reaction. As such, every person’s body responds differently to different allergens, meaning that hives is not a contagious condition, rather an individual response to a specific trigger.

     

    4. Where do hives appear on your body?

    While there are some specific areas of the body on which hives appear in some cases, usually there is no magic recipe for this. Therefore, you can get:

    • All over body
    • On the skin
    • On face
    • On lips
    • Hives eyes, including hives around eyes and hives under eyes;
    • Hives behind ears
    • Hives neck
    • Hives on chest
    • Hives on stomach
    • Hives under arms
    • Hives hands
    • Hives on feet.

     

    Conclusion

    Hives or urticaria is a very common skin condition, representing the immune system’s reaction to a trigger. Its symptoms can cause some difficulties in the day-to-day activities, impacting the quality of life, but there are multiple ways to treat and alleviate the discomfort caused by hives. Don’t forget to consult with a medical professional in case of chronic hives or worsening of the symptoms.  

    Patients with urticaria account for a sizable share of referrals to allergy clinics. There are several causes of urticaria, and the clinical history is crucial in determining probable causes; nonetheless, urticaria is frequently idiopathic. 

    Urticaria may be a sign of a serious underlying medical illness in a tiny percentage of people, or allergic symptoms may worsen to produce systemic responses, and it is critical to identify these individuals and remember that severe urticaria is an unpleasant and burdensome condition.